chrome/browser/chromeos/input_method/browser_state_monitor.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/chromeos/input_method/browser_state_monitor.h"
   6
   7 #include "base/logging.h"
   8 #include "chrome/browser/chrome_notification_types.h"
   9 #include "chrome/browser/chromeos/input_method/input_method_util.h"
  10 #include "chromeos/ime/input_method_delegate.h"
  11 #include "content/public/browser/notification_service.h"
  12
  13 namespace chromeos {
  14 namespace input_method {
  15
  16 BrowserStateMonitor::BrowserStateMonitor(
  17     const base::Callback<void(InputMethodManager::State)>& observer)
  18     : observer_(observer),
  19       state_(InputMethodManager::STATE_LOGIN_SCREEN) {
  20   notification_registrar_.Add(this,
  21                               chrome::NOTIFICATION_LOGIN_USER_CHANGED,
  22                               content::NotificationService::AllSources());
  23   notification_registrar_.Add(this,
  24                               chrome::NOTIFICATION_SESSION_STARTED,
  25                               content::NotificationService::AllSources());
  26   notification_registrar_.Add(this,
  27                               chrome::NOTIFICATION_SCREEN_LOCK_STATE_CHANGED,
  28                               content::NotificationService::AllSources());
  29   // We should not use ALL_BROWSERS_CLOSING here since logout might be cancelled
  30   // by JavaScript after ALL_BROWSERS_CLOSING is sent (crosbug.com/11055).
  31   notification_registrar_.Add(this,
  32                               chrome::NOTIFICATION_APP_TERMINATING,
  33                               content::NotificationService::AllSources());
  34
  35   if (!observer_.is_null())
  36     observer_.Run(state_);
  37 }
  38
  39 BrowserStateMonitor::~BrowserStateMonitor() {
  40 }
  41
  42 void BrowserStateMonitor::Observe(
  43     int type,
  44     const content::NotificationSource& source,
  45     const content::NotificationDetails& details) {
  46   const InputMethodManager::State old_state = state_;
  47   switch (type) {
  48     case chrome::NOTIFICATION_APP_TERMINATING: {
  49       state_ = InputMethodManager::STATE_TERMINATING;
  50       break;
  51     }
  52     case chrome::NOTIFICATION_LOGIN_USER_CHANGED: {
  53       // The user logged in, but the browser window for user session is not yet
  54       // ready. An initial input method hasn't been set to the manager.
  55       // Note that the notification is also sent when Chrome crashes/restarts
  56       // as of writing, but it might be changed in the future (therefore we need
  57       // to listen to NOTIFICATION_SESSION_STARTED as well.)
  58       DVLOG(1) << "Received chrome::NOTIFICATION_LOGIN_USER_CHANGED";
  59       state_ = InputMethodManager::STATE_BROWSER_SCREEN;
  60       break;
  61     }
  62     case chrome::NOTIFICATION_SESSION_STARTED: {
  63       // The user logged in, and the browser window for user session is ready.
  64       // An initial input method has already been set.
  65       // We should NOT call InitializePrefMembers() here since the notification
  66       // is sent in the PreProfileInit phase in case when Chrome crashes and
  67       // restarts.
  68       DVLOG(1) << "Received chrome::NOTIFICATION_SESSION_STARTED";
  69       state_ = InputMethodManager::STATE_BROWSER_SCREEN;
  70       break;
  71     }
  72     case chrome::NOTIFICATION_SCREEN_LOCK_STATE_CHANGED: {
  73       const bool is_screen_locked = *content::Details<bool>(details).ptr();
  74       state_ = is_screen_locked ? InputMethodManager::STATE_LOCK_SCREEN :
  75           InputMethodManager::STATE_BROWSER_SCREEN;
  76       break;
  77     }
  78     default: {
  79       NOTREACHED();
  80       break;
  81     }
  82   }
  83
  84   if (old_state != state_ && !observer_.is_null())
  85     observer_.Run(state_);
  86
  87   // Note: browser notifications are sent in the following order.
  88   //
  89   // Normal login:
  90   // 1. chrome::NOTIFICATION_LOGIN_USER_CHANGED is sent.
  91   // 2. Preferences::NotifyPrefChanged() is called. preload_engines (which
  92   //    might change the current input method) and current/previous input method
  93   //    are sent to the manager.
  94   // 3. chrome::NOTIFICATION_SESSION_STARTED is sent.
  95   //
  96   // Chrome crash/restart (after logging in):
  97   // 1. chrome::NOTIFICATION_LOGIN_USER_CHANGED might be sent.
  98   // 2. chrome::NOTIFICATION_SESSION_STARTED is sent.
  99   // 3. Preferences::NotifyPrefChanged() is called. The same things as above
 100   //    happen.
 101   //
 102   // We have to be careful not to overwrite both local and user prefs when
 103   // preloaded engine is set. Note that it does not work to do nothing in
 104   // InputMethodChanged() between chrome::NOTIFICATION_LOGIN_USER_CHANGED and
 105   // chrome::NOTIFICATION_SESSION_STARTED because SESSION_STARTED is sent very
 106   // early on Chrome crash/restart.
 107 }
 108
 109 }  // namespace input_method
 110 }  // namespace chromeos